[1] Univ Cape Coast, Coll Hlth & Allied Sci, Sch Allied Hlth Sci, Dept Optometry & Vis Sci, Cape Coast, Ghana
[2] Salus Univ, Dept Biomed, 8360 Old York Rd, Elkins Pk, PA 19027 USA
[3] Western Sydney Univ, Bathurst Rural Clin Sch BRCS, Sch Med, POB 9008, Bathurst, NSW 2795, Australia
[4] Univ KwaZulu Natal, African Vis Res Inst, Discipline Optometry, Westville Campus, ZA-3629 Durban, South Africa
[5] Univ Calabar, Dept Publ Hlth, Epidemiol & Biostat Unit, Calabar, Cross River Sta, Nigeria
[6] Univ Highlands & Isl, Ctr Hlth Sci, Dept Optometry, Inverness IV2 3JH, Scotland
[7] KNUST, Coll Sci, Dept Optometry & Visual Sci, AK 385-1973, Kumasi, Ghana
[8] Univ Otago, Dunedin Sch Med, Dept Med, Otago, New Zealand
[9] Western Sydney Univ, Sch Hlth Sci, Campbelltown, NSW 2560, Australia
[10] Univ Calabar, Coll Med Sci, Fac Allied Med Sci, Dept Publ Hlth, Calabar, Cross River Sta, Nigeria
[11] Univ New South Wales, Sch Optometry & Vis Sci, Sydney, NSW, Australia